The present invention relates to a graphic information processing unit, more particularly, to a graphic display information memory system that easily performs indexing as well as editing, while significantly reducing memory capacity requirements.
Recently, a variety of designing techniques have been developed, for example, a CAD process enabling the operator to effectively perform designing by exchanging dialogues with a computer via a graphic display, and a CAM process for performing designing related to productive operations by using computers, thus making it possible to create complex and large drawings.
Conventionally, when using any of the existing graphic display information processing units, to easily edit information such as by addition, deletion or change, the graphic display information is defined to use segments (which are groups the graphic display elements, pixels) that denote the minimum unit for composing information. For example, 1 segment of data comprising 256 bytes of a fixed data length has been stored in memory. Nevertheless, such a method for storing graphic display information in memory with a fixed data bit length results in inefficient use of the data memory area and as a result, memory capacity has to be expanded significantly.